And Reagan's tax increases would never have been approved by Lincoln!
Reagan cut taxes once in office and then raised them again for SS-did he not?
We had Whig Presidents and Congresses before (as well as Federalists) and the nation survived.
Wrong. Reagan cut taxes starting in 1981 over three stages through 1984 IIRC. The 1986 tax cut was a mixed bag the further cut the rates in the upper income tax brackets but raised them indirectly through capital gains and the removal of state tax and consumer loans deductions - a product of the Democrats in Congress (specifically Gephardt and Bill Bradley) more than anything Reagan did.
The Social Security Act of 1983 subjected half of the program's handouts to income tax, which technically speaking is NOT a tax hike since the fee is extracted from a government entitlement rather than actual earned income.
In any case however, you have absolutely no evidence that Lincoln would've found anything Reagan did to social security objectionable beyond your own uninformed speculation. As to whether he would've found the Reagan tax cuts objectionable, that much may be concluded on the fact that in his own lifetime and 30+ year political career Lincoln never once wavered on raising taxes and never saw a tax hike that he did not like.